JP3262106B2 - Copper foil with resin and printed circuit board using the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin-coated copper foil and a printed circuit board using the same, and more particularly to a resin having a resin layer composed of a completely cured resin and a semi-cured resin on the matte side of the copper foil. The present invention relates to an attached copper foil and a printed circuit board using the same.

[0002]

2. Description of the Related Art Conventionally, a resin-coated copper foil constituting a surface layer of a laminated printed circuit board has been disclosed in JP-A-63-58997.
The copper foil with a resin described in Japanese Patent Application Laid-Open No. H10-209,052 is known.

FIG. 3 is a sectional view showing the structure of a conventional copper foil with resin.

Referring to FIG. 3, a conventional copper foil with resin 2
Numeral 0 denotes a laminate of a resin layer 23 composed of a first resin layer 23a composed of a completely cured resin and a second resin layer 23b composed of a semi-cured resin laminated on the first resin layer on a mat surface 22 of a copper foil 21. It is configured.

[0005]

As a method for manufacturing a high-definition printed circuit board, a build-up method of thermocompression bonding a resin-coated copper foil to the surface of a core substrate of the printed circuit board has been adopted. In the build-up method, controlling the thickness of the insulating layer formed between the core substrate and the copper foil is an important issue. Since the thickness of the insulating layer is generally as thin as several tens of μm, there is a problem that the variation in the thickness directly affects the characteristics of an electric circuit to be mounted. In the build-up method using resin-coated copper foil, the resin formed on the resin-coated copper foil side is affected by variations in the resin layer, which is the insulating layer on the resin-coated copper foil side, and variations in the thermocompression bonding conditions of the vacuum heat press. There was a problem that the thickness of the insulating layer fluctuated due to a change in the amount of flow. In a conventional resin-coated copper foil, the first resin layer applied first time is completely cured, and a resin in a semi-cured state is laminated thereon. However, it is difficult to uniformly form the first resin layer. It was difficult. Further, in order to completely cure the first resin layer, there is a problem that a temperature setting for curing exceeding 200 ° C. or an oxygen-free state is required depending on the resin. As a result, there is a drawback that a large cost is required to construct a conventional production line for a copper foil with a resin, and the production cost of the copper foil with a resin is high.

SUMMARY OF THE INVENTION An object of the present invention is to provide an inexpensive resin which can stably and uniformly obtain the thickness of a bonded and cured insulating layer when a copper foil with a resin is laminated by heating and pressing on a core substrate of a printed circuit board. The purpose is to obtain copper foil.

Another object of the present invention is to provide a printed circuit board having excellent electrical characteristics by stably and uniformly forming the thickness of an insulating layer of a printed circuit board on which a resin-coated copper foil is laminated. .

[0008]

The resin-coated copper foil of the present invention is characterized in that a resin layer is formed by kneading a completely cured spherical resin in a semi-cured resin layer.

[0009] The composition of the semi-cured resin layer and the spherical resin is the same component composition.

The maximum diameter of the spherical resin is designed based on the thickness of the insulating layer after being laminated on the printed circuit board, and is designed to be equal to or less than the same dimension as the thickness of the insulating layer.

[0011] The semi-cured resin and the spherical resin are both thermosetting resins.

It is characterized in that the thermosetting resin is one of an epoxy resin, a polyimide resin, a polyester resin, a phenol resin and a thermosetting resin containing polyphenylene oxide.

The printed circuit board according to the present invention is characterized in that the resin-coated copper foil according to the present invention is laminated on a core substrate constituting the printed circuit board by heating and pressing.

[0014]

Next, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a sectional view showing an embodiment of a copper foil with resin according to the present invention.

In the embodiment of the present invention shown in FIG. 1, a resin-coated copper foil 1 has a resin layer 4 formed on a mat surface 3 of a copper foil 2. The resin layer 4 includes a completely cured spherical resin 5 and a semi-cured resin 6.
The spherical resin 5 is uniformly dispersed and kneaded in the semi-cured resin 6. It is best that the spherical resin 5 and the semi-cured resin 6 have the same composition in terms of electrical characteristics. For example, epoxy resin, polyimide resin, polyester resin, phenol resin, and polyphenylene oxide-containing thermosetting resin A thermosetting resin is used. The spherical resin 5 is a completely cured resin, and an optimum particle diameter is appropriately selected according to the design of the insulating layer of the laminated printed circuit board. The maximum diameter of the spherical resin 5 is designed based on the thickness of the insulating layer after being laminated on the core substrate constituting the printed circuit board, and is desirably not more than the same dimension as the thickness of the insulating layer. Generally 50
A particle having a particle size in the range of μm to 100 μm is used.

Next, a specific method for producing the resin-coated copper foil according to the present invention will be described. First, the completely cured spherical resin 5 is uniformly kneaded in the uncured thermosetting resin. Subsequently, the kneaded thermosetting resin is applied to the mat surface 3 of the copper foil 2.
It is applied on top and heated under predetermined conditions according to the resin employed to react to a semi-cured state. The resin-coated copper foil 1 according to the present invention in which the resin layer 4 in which the spherical resin 5 is dispersed in the semi-cured resin 6 is applied on the matte surface 3 of the copper foil 2 in this manner.
Is obtained.

Next, a printed circuit board using the resin-coated copper foil according to the present invention will be described.

FIG. 2 is a sectional view of a printed circuit board using the resin-coated copper foil according to the present invention.

The printed circuit board 7 of FIG. 2 is manufactured by a build-up method in which the resin-coated copper foil 1 according to the present invention described in FIG. You.

Referring to FIG. 2, the semi-cured resin 6 of the resin-coated copper foil 1 is semi-cured by the pressurizing and heating press machine, so that it is once softened and traces the uneven portion of the core substrate 8 and partially laminated. The excess resin 9 flows out of the stacked printed circuit boards 7 together with the air remaining between the layers.

Since the spherical resin 5 uniformly dispersed and kneaded in the semi-cured resin 6 is in a completely cured state, it does not soften at the time of heating and pressing at the time of lamination. In addition, by selecting a pressing condition under which the spherical resin 5 does not cause a dimensional change, it is possible to stably and uniformly form an insulating layer having a size determined by the diameter of the spherical resin 5.

The diameter of the spherical resin 5 is designed on the basis of the insulating layer thickness 10 after being laminated on the core substrate 8 constituting the printed circuit board 7, and it is desirable that the diameter is substantially equal to or smaller than the insulating layer thickness 10.

The spherical resin 5 and the semi-cured resin 6 are resins having the same composition, and the electrical characteristics such as the relative dielectric constant and the dielectric loss tangent of the insulating layer finally formed by laminating and curing are uniform. .

The thickness and electrical characteristics of the insulating layer of the printed circuit board 7 laminated using the resin-coated copper foil 1 according to the present invention are determined by the conventional resin-coated copper foil comprising only a semi-cured resin layer or the completely cured first resin. The layer and the semi-cured second resin layer are separately formed, and are more uniform than in the case where a resin-attached copper foil laminated in advance is used.

[0026]

As described above, the resin-coated copper foil of the present invention is obtained by uniformly dispersing and kneading a completely cured granular resin in a semi-cured resin layer on a copper foil mat, and applying it in advance. When laminated by heating and pressing on a core substrate of a printed circuit board, the cured insulating layer can be formed stably and uniformly, and an inexpensive resin-coated copper foil can be obtained.

Further, the printed circuit board using the resin-coated copper foil according to the present invention has a thickness in which the insulating layer between the copper foil obtained by laminating the resin-coated copper foil and the core substrate is kneaded in a semi-cured resin. Since the thickness is finally determined by the diameter of the granular resin of the cured resin, the thickness of the insulating layer of the printed circuit board can be formed stably and uniformly, and a printed circuit board having good electric characteristics can be obtained.

[Brief description of the drawings]

FIG. 1 is a sectional view showing one embodiment of a copper foil with resin of the present invention.

FIG. 2 is a cross-sectional view of a printed circuit board using the resin-coated copper foil of the present invention.

FIG. 3 is a sectional view of a conventional copper foil with resin.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Copper foil with resin 2 Copper foil 3 Matt surface 4 Resin layer 5 Spherical resin 6 Semi-cured resin 7 Printed board 8 Core board 9 Excess resin 10 Insulation layer thickness 20 Copper foil with resin 21 Copper foil 22 Mat surface 23 Resin layer 23a 1 resin layer 23b 2nd resin layer

────────────────────────────────────────────────── ─── Continuation of front page (56) References JP-A-11-320758 (JP, A) JP-A-8-323916 (JP, A) JP-A-7-202364 (JP, A) JP-A-7-202 154067 (JP, A) JP-A-3-231840 (JP, A) JP-A-2-206542 (JP, A) JP-A-11-135952 (JP, A) JP-A-10-249993 (JP, A) (58) Field surveyed (Int. Cl. ⁷ , DB name) B32B 15/08

Claims (6)

(57) [Claims] 1. A resin-coated copper foil having a resin layer formed on the matte side of a copper foil, wherein the resin layer is formed by kneading a completely cured spherical resin in a semi-cured resin layer. Copper foil with resin. 2. The resin-coated copper foil according to claim 1, wherein the composition of the semi-cured resin layer and the composition of the spherical resin are the same. 3. A design wherein the maximum diameter of the spherical resin is designed based on the thickness of an insulating layer after being laminated on a core substrate constituting a printed circuit board, and is set to be equal to or less than the same dimension as the thickness of the insulating layer. The copper foil with resin according to claim 1. 4. The semi-cured resin layer and the spherical resin are both thermosetting resins.
4. The copper foil with resin according to any one of 3. 5. The resin-coated copper according to claim 4, wherein the thermosetting resin is one of an epoxy resin, a polyimide resin, a polyester resin, a phenol resin, and a thermosetting resin containing polyphenylene oxide. Foil. 6. A printed board, wherein the copper foil with resin according to any one of claims 1 to 5 is laminated by heating and pressing on a core board constituting the printed board.